Urinary incontinence (UI), the involuntary loss of urine, is estimated to affect approximately one in three adult women. Due to such factors as pregnancy and childbirth, menopause, and the structure of the female urinary tract, UI is twice as prevalent in women as in men. UI can also arise from such causes as neurologic injury, birth defects, stroke, multiple sclerosis, and the physical problems associated with aging. UI can run the gamut from slightly bothersome to completely debilitating: some women suffering from UI lose a few drops of urine during activities such as running or coughing, while others may feel a strong, sudden urge to urinate just before losing a large amount of urine. For some women suffering from UI, the risk of public embarrassment can keep them from enjoying activities with family and friends.
Stress urinary incontinence (SUI), also known as effort incontinence, is typified by loss of small amounts of urine associated with movements that increase the intra-abdominal pressure, thereby increasing the pressure on the bladder. If the support provided to the urethra by the fascia of the pelvic is insufficient, then at times of increased intra-abdominal pressure, for example, during movements that increase the intra-abdominal pressure and hence the pressure on the urinary bladder such as coughing, laughing, sneezing, and exercise, the urethra can move downward, allowing urine to pass.
The anatomic structures that prevent SUI in healthy women can be divided into two systems, a sphincteric system and a support system. The action of the vesical neck and urethral sphincteric systems at rest constrict the urethral lumen and keep urethral pressure higher than the pressure in the urinary bladder. The striated urogenital sphincter, the smooth muscle sphincter in the vesical neck, and the circular and longitudinal smooth muscle of the urethra all contribute to the pressure that at least partially closes the urethra. The mucosal and vascular tissues that surround the lumen provide a hermetic seal, and the connective tissues in the urethral wall also aid coaptation. Decreases in striated muscle fibers occur with age. The supportive hammock under the urethra and vesical neck provides a firm backstop against which the urethra is compressed during increases in abdominal pressure to maintain a sufficient urethral pressure to keep it closed as the pressure in the urinary bladder increases. The stiffness of this supportive layer is presumed to be important to the degree to which compression of the urethra can occur.
While SUI is more common in older women than in younger women, it is not an inevitable consequence of aging. As the population ages, there is an increasing need for nonsurgical methods for treating SUI. One such method is to place an insert in the vagina which presses against the urethra, providing support for the urethro-vaginal myofascial area and thereby preventing involuntary loss of urine. One approach to the construction of such an insert is exemplified by the devices disclosed in U.S. Pat. No. 7,771,344 and in U.S. patent application Ser. No. 10/598,872, now U.S. Pat. No. 8,727,961. These devices comprise an insert that provides a constant pressure to the urethra, preventing SUI. The constant pressure provided by such devices is their primary disadvantage. Increased pressure on the urethra to prevent incontinence is only necessary during the brief intervals of increased intra-abdominal pressure described above.
A second approach is taken in the design of the device disclosed in U.S. Pat. No. 7,736,298. This device comprises two ends, a distal deformable end and a proximal end that cannot be deformed. The device is inserted such that the distal end is adjacent to the urinary bladder. When the bladder is full, distal end is deflected, and the leverage provided by the increased pressure from the bladder deflects proximal end in the opposite direction, closing the urethra. While this device has the advantage that it is activated only when the bladder pressure is high, it also has the disadvantage that it is essentially rigid and provides a constant pressure to the urethra as long as bladder is full and provides a constant pressure to the urethra as long as bladder is full. This rigidity means that the device must be provided in a variety of sizes, because one standard size is unlikely to fit all women.
A third approach is to design devices that are partially or wholly inflatable such that pressure is applied to the urethra only when the device is in its inflated state. Examples of such devices are the commercially available “Inflatoball” sold by Cooper Surgical and devices such as those disclosed in U.S. Pat. No. 4,920,986 and U.S. Pat. No. 6,189,535. In these devices, however, a source of air external to the body is necessary, or means external to the body (e.g. a syringe) are necessary to deflate the device. Furthermore, these devices must also be provided in a variety of sizes so that any individual woman can be guaranteed one that has the proper fit.
Thus, a device for treating urinary incontinence in females that uses hydraulic means (e.g. inflation or deflation of a portion of the device) to provide the necessary pressure, that is truly self-contained once it is inserted, and that can be adjusted to fit the body of a specific user, remains a long-felt and unmet need. In addition, there remains a long-felt and unmet need for a device that can act both as a means for preventing urinary incontinence and as a means for rehabilitating a female suffering from SUI by increasing the strength of the pelvic floor muscles.